Fz: Setting Zero Flow Frequency; Ft: Shutdown Threshold Setting; So: Dry Running Factor - DAB PWM 203 Installations- Und Wartungsanleitungen

Table of correspondence of diameters and k-factors for flow sensor F3.00
Pipe diameter [inch]
1/2
3/4
1
1 1/4
1 1/2
2
2 1/2
3
3 1/2
4
5
6
8
10
12
14
16
18
20
24
Table 20: Diameter of pipelines, FK conversion factor, minimum and maximum admissible flow
CAUTION: always refer to the manufacturer's installation notes and compatibility of electric parameters of the flow sensor and those
of the inverter, as well as exact correspondence of connections. Incorrect settings will cause false flow readings with possible
undesired shutdown or continuous operation without stops.
6.5.12

FZ: Setting zero flow frequency

It expresses the frequency below which it may be considered that there is zero flow in the system.
It can be set only if FI has been set to operate without a flow sensor. If FI has been set to operate with a flow sensor, the parameter
FZ is blocked. The parameter disabled message is indicated by an icon showing a padlock.
If FZ = 0 Hz is set the inverter will use the self-adaptive operating mode, instead if FZ ≠ 0 Hz is set then the inverter will use the
minimum frequency operating mode (see par. 6.5.9.1).
6.5.13

FT: Shutdown threshold setting

This sets a minimum flow threshold, below which, if there is pressure, the inverter stops the electric pump.
This parameter is used in both operation with and without flow sensor, but the two parameters are different; therefore even when the
setting of FI is changed, the FT value remains consistent with the type of operating mode without overwriting the two values. In
operation with the flow sensor, the FT parameter is in litres/minute or gal/min, while without the flow sensor the value is
adimensional.
In the same page, as well as the flow shutdown setting FT, the measured flow rate is displayed, to facilitate user operations. This
appears in a highlighted box below the name of the FT parameter, and bears the text "fl". In operating mode without flow sensor, the
minimum flow "fl" displayed in the box is not immediately available, and may take a few minutes of operation for the figure to be
calculated.
CAUTION: if an excessively high FT value is set, undesired shutdown may occur; if the value is too low operation may be continuous
without stops.
6.5.14

SO: Dry running factor

This sets the minimum dry running factor threshold below which the lack of water is detected. The dry running factor is a non-
dimensional parameter obtained by combining absorbed current and the pump power factor. Thanks to this parameter it is possible
to correctly establish when there is air in the impeller of a pump or if the suction flow is interrupted.
This parameter is used on all multi inverter systems and on all systems without flow sensor. If the pump functions only with one
inverter and flow sensor SO is blocked and disabled.
Internal DN pipe
diameter [mm]
15
20
25
32
40
50
65
80
90
100
125
150
200
250
300
350
400
450
500
600
ENGLISH
Minimum flow l/min
K-factor
225,0
142,0
90,0
60,7
42,5
24,4
15,8
11,0
8,0
6,1
4,0
2,60
1,45
0,89
0,60
0,43
0,32
0,25
0,20
0,14
104
Maximum flow
1,6
2,8
4,4
7,2
11,3
17,7
29,8
45,2
57,2
70,7
110,4
159,0
282,6
441,6
635,9
865,5
1130,4
1430,7
1766,3
2543,4
l/min
85
151
236
386
603
942
1592
2412
3052
3768
5888
8478
15072
23550
33912
46158
60288
76302
94200
135648